An imaging lens SL mounted in a digital single lens reflex camera 1 is composed of, in order from an object side, a first lens group G1 having negative refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having positive refractive power, wherein upon focusing on a near-distance object point from an infinite-distance object point, at least one of the first lens group G1 and the second lens group G2 is moved so as to change a distance between the first lens group G1 and the second lens group G2, and the imaging lens satisfies a given conditional expression, thereby providing a downsized imaging lens suited to an imaging apparatus such as a single lens reflex camera, having a less of change in overall length and optimal to driving an intra-lens-barrel motor.